Initial fs implementation for UEFI

- Only works in the root volume
- Implement truncate, create_new, etc
- Implement getting created, modified and accessed times.
- Implement file copy
- Implement exists
- Implement mkdir
- Implement rename

Avoiding directory stuff for now

Signed-off-by: Ayush Singh <ayushdevel1325@gmail.com>

Author: Ayush1325

library/std/src/lib.rs

@@ -346,6 +346,7 @@
 #![feature(prelude_2024)]
 #![feature(ptr_as_uninit)]
 #![feature(ptr_mask)]
+#![feature(ptr_metadata)]
 #![feature(slice_internals)]
 #![feature(slice_ptr_get)]
 #![feature(slice_range)]